What Does The A Button Do In A Car?

Where is the ‘A’ button?

The A button can be found in many modern vehicles, usually among the center console buttons.

What does the ‘A’ button do?

Pushing the A button will disable the automatic start-stop function for that drive.

What is automatic start-stop?

Automatic start-stop is a system that shuts down the engine when the vehicle is stationary. For example, when stopped at a red light or when stopped in congested traffic.

The system design is engineered to increase fuel economy and reduce emissions.

How does it work?

The vehicle must be at a complete stop and in a forward gear with the brake pedal depressed.

According to Mopar, the A/C or heating airflow may be reduced. This is due to the power being drawn from the battery (not to be confused with a hybrid battery) instead of from the engine, whilst it is shut off. This should go back to normal when the engine re-starts.  

In Jeeps, a green icon will display on the dash to let you know the engine has stopped. A message will also be displayed letting you know that the system is ready and active. Upon the release of pressure from the brake pedal, the engine will restart.

Are there conditions where start-stop won’t activate?

Yes. Certain safety conditions must be met before the system will activate. If you come to a stop and the vehicle engine does not shut off, use the arrow buttons on the left side of the steering wheel to navigate to the start-stop settings on your dash display.

There it will tell you what condition has not been met. For example, the steering wheel is turned or the driver seatbelt is not fastened. Other conditions might include;

• Driver door not closed
• Blower on full defrost
• Blower on MAX A/C
• Cabin temperature not reached
• The shifter is in reverse
• Hood is open
• Low battery power
• Battery too hot or too cold
• Vehicle in is 4 LOW
• Less the 5mph achieved since the last start-stop activation
• Adaptive Cruise Control is on

Using the ‘disable auto start-stop’ button

The button as shown in the photo is to disable this feature. Pushing the A button means the engine will not shut off when the vehicle is stopped.

When the light illuminates on the button, this means the system is OFF. Note that it only disables it until you manually turn off the engine. Once you restart the vehicle it will become active again. There is no way to permanently disable the feature as recommended by Jeep.

Now you know what the A button does!

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